In any blueprint, if a discovery does not find anything, then its the indicators
Within the indicators, you have File & Registry Indicators along with the Network Probes, but also, just as important, Discovery Verification Rules. For this blueprint, it is looking to confirm if the $(Version) is 11.*** where $(Version) is looking for "Version" $(RegistryRoot)\Setup\Version (located in 'Component Parameters and Variables').
If the above is valid, since there are no file indicators for this blueprint, take a look at the registry Indicators, make sure they all exist within HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server